Methods of producing cocoa butter

ABSTRACT

Process of extracting cocoa butter from sources thereof by use of supercritical gases which are solvents therefor, especially carbon dioxide.

United States Patent Roselius et al. 1 Dec. 2, 1975 [54] METHODS OFPRODUCING COCOA 3,064,018 11/1962 Bruera 260/4l2.8 BUTTER 3093,48O6/1963 Arnold 260/4128 [75] Inventors: Wilhelm Roselius, Bremen-St.FOREIGN PATENTS OR APPLICATIONS Magnus; Otto Vitzthum, Bremen; Peter HBremenJ-esum l of 1,057,9II United Kingdom Germany [73] Assignee:Studiengesellschaft Kohle m.b.II., Primary ExamiflerElbeft'L- RobertsMulheim (Ruhr), German Attorney, Agent, or Firm--Burgess, Dinklage & 22Filed: May 23, 1973 Sprung [21] Appl. No.: 363,098

[57] ABSTRACT [52] US. Cl 260/412.8; 260/412.8 [51 Int. cl. (:1 18 1/10Process extracting Cocoa butter from Sources 58 Field of Search260/4l2.8 thereof y s f supercritical gases which are Solvents therefor,especially carbon dioxide. [56] References Cited UNITED STATES PATENTS'9 Claims, 1 Drawing Figure 2,735,624 2/1956 Beck 260/412.8

US. Patent Dec. 2, 1975 METHODS OF PRODUCING COCOA BUTTER This inventionrelates to a method for producing cocoa butter.

The methods of producing cocoa butter which are customary at the presenttime may be classifiedas follows:

1. Expression of the cocoa butter from the cocoa mass;

2. Expression of cocoa butter from cocoa nibs; and

3. Extraction of cocoa butter from cocoa mass, cocoa nibs, cocoapress-cakes, or cocoa powder by means of organic solvents.

In countries where particularly high quality is demanded, only pressingmethods rather than extraction methods may be used. The main reason forthis is that in the latter case the relatively high boiling pointsolvents have to be removed not only from the cocoa butter but also fromthe extraction residue, and it is doubtful whether it is possible toremove all residues or traces. Moreover, in the case of extraction theentire fat content is usually removed from the cocoa, so that theremaining cocoa powder is practically valueless. In addition, theextraction methods are applied to damaged cocoa material and to cocoaand chocolate waste, and this has led to the discrediting of the methodas the low quality cocoa butter produced by this means is frequentlyadded as an adulterant to high grade cocoa butter. Detection methodshave even been evolved for this reason, in order to enable the additionof extract butter to be detected analytically, (E. Lauber, A. Fincke, H.Meyer, J. Wurziger, et al., for a survey of literature on this subjectsee J. Kleinert, Gordain 64, 174-189 1964)).

For the processing of cocoa mass, pressing methods have been introducedfor some time, whereas the production of cocoa butter from nibs incontinuously working expeller presses is more recent. Compared with thepressing of cocoa mass, the use of'screw or expeller presses leads to aproduct containing a particularly high proportion of waste matter, whichin both cases must be removed. The processing of theresulting pressresidues to form cocoa powder is difficult, while it is also difficultto obtain a constant fat content in the residue.

Pressing methods have the common feature that they entail considerabletechnical effort and consequently high cost.

The present invention provides a new method for the production of cocoabutter from cocoa nibs or cocoa mass, and in which it is in principleimmaterial whether or not the cocoa nibs are roasted or whether or notthe material has been alkalinised. The method is based on theobservation that various gases, which are supercritical in respect ofpressure and temperature, constitute excellent solvents for cocoa fatwhich moreover are completely unobjectionable from the health point ofview, i.e. are food-acceptable.

Accordiing to the invention there is provided a method for theproduction of cocoa butter from cocoa mass or from unroasted or roastedcrushed cocoa nibs by extraction withsolvents wherein theco'coa productis subjected to extraction with food-acceptable gas which issupercritical in respect of both pressure and temperature. The cocoabutter can be thereafter separated from the solution elg. by varying thepressure and/or temperature.

a 2 Carbon dioxide is particularly preferred as the extraction medium,but the same results are obtained if use is made instead of N 0, SF ,CFCL, CHFgCl,

CF =CH C;,F,,,CHF,,, ethane and ethylene, which are unobjectionablegases from the point of view of health. To attain the degree of purityrequired to be foodacceptable, the selected solvent can be distilled orotherwise purified before use.- I

When solvents other than .CO- are used, the limits in respect ofpressures and temperatures which are indicated in Cases 1 to 4hereinafter should be obtained correspondingly from critical datadescribed in literature.

It has been found that, for'example, CO will dissolve cocoa fat even inthe liquid state, but when it passes to the supercriticalstate theproperties of CO are modified abruptly in. the direction of considerablygreater dissolving power. This also applies to the gases mentionedabove.

By way of example, a specific embodiment of the invention will now bedescribed with reference to the accompanying drawing which shows,diagrammatically, the apparatus employed. The embodiment involves theuse of carbon dioxide as the extraction solvent gas, but it is to beunderstood that other suitable solvent gases, for example those listedabove, or mixtures thereof could be used in place of the carbon dioxide,appropriate changes being made to take account of different criticalpressures and temperatures of such a solvent gas.

In a preferred embodiment of the invention which is illustrated by theaccompanying drawings, the procedure is as follows: (the values P an d trelate to the pressure and temperature conditions in the extractionvessel 11, while P 2 I relate to the extraction vessel 12).

Cocoa mass or crushed cocoa nibs are introduced without specialpre-treatment and without additions (such as for example lecithin inthepressing method) into the pressure tube 13 and the entire plant isfirst flushed free of air by means of CO .The extraction medium is thendrawn by suction from the liquid gas tanks and the medium, which in thefirst instance is still liquid, is forced by means of a pump into theheat exchanger 14, in which it is brought to supercritical conditions inrespect of pressure and temperature. It then enters tube 13, passesthrough the contents of the latter, and is thereby charged with cocoafat in the form of a supercritical solution. The inlet and outletapertures of the vessel are closed by metal filter discs (filterthreshold 3 micron) so that the entrainment of particles of cocoa is notpossible. The charged supercritical gas phase is now expanded by meansof a throttle valve 15 into the vessel 12 and it is ensured that thepressure falls to values lower than PM, The system thereby separates,i.e. the pure cocoa butter is separated. If the temperature is left atvalues slightly above t (or the fraction of water likewise entrained bythe gas from the cocoa will not be separated from the mixture and willbe further entrained by the current of CO which is' now free of extract.The cocoa butter is thus-practically free from water. In principle itshould be observed at this point that a reduction of pressure and/or araising of the temperature will lead to the same effect, namely thedisintegration of the system, so that a number of variants of the methodare conceivable. When the desired pressure and temperature conditionshave been adjusted in the vessels, the flow of gas from the liquid gastanks is stopped and the circuit closed. The valves l5,l6,l7,l8,l9,20are for this purpose open and all others closed. The gas leaving thevessel 12 is liquefied in the heat exchanger 21, delivered by the pumpinto the heat exchanger 14, in which it is brought to supercriticalconditions again, and it passes as pure solvent back into the tube 13,and so on. Instead of the liquid gas pump it is also possible to use acompressor, in which case the liquefaction of the gas is not necessary.Which of these measures is selected will depend only on technicalcircumstances in the process. since in this case other heat exchangersare necessary.

As previously mentioned, pressures above 75.3 at., which isapproximately equal to P and temperatures above t are necessary for theextraction. In practice a pressure above 100 atmospheres gauge, andpreferably between 200 and 400 atmospheres gauge, is used. It is aparticular feature of the method that in respect of temperature it isonly necessary to work slightly above the critical temperature of COthat is to say above 31.6C, preferably between and 60C.

In practice the heat exchangers 14, 21 and 22 will be connectedtogether, thus leading to a procedure which is very advantageous inrespect of energy. and therefore economical.

By way of the valves l8, 19 an optical sight cell, through which part ofthe charged gas current flows, is incorporated in a by-pass. It isequipped with a light source, UV-detector, amplifier and recorder orelectrical controller. This arrangement makes it possible for the courseof the extraction to be followed accurately with the aid of calibrationcurves, and to switch off the installation as soon as the desiredproportion of fat has been removed from the cocoa contained in vessel11. ln this way any desired degree of extraction can be achieved andreliably reproducible results will be achieved, which are better thanthe values obtained by conventional methods.

After completion of the processing, vessel 12 is first closed and allthe gas contained in the remainder of the circuit is pumped back intothe tanks. Valves l6,15,20,23, 24 are for this purpose closed, and allothers are opened. Consequently practically no losses occur.

A slightly yellowish cocoa butter is obtained which is completely freefrom particles of cocoa matter and which can be used without furtherfiltration or other processing, while it is in every respect, includingaroma, equivalent to a conventional press product of the highestquality. A feature of the method which should be emphasised is that thecomposition of the cocoa butter will not vary even if not all but onlypart of the cocoa fat is extracted.

lf crushed nibs are used, the residue found in 11 will be a materialwhich is unchanged in colour and structure and which can easily befurther processed. When cocoa mass is used, a powdery or crumblymaterial is obtained which can easily be handled and the colour of whichhas been only slightly lightened. The nibs or masses which haveundergone extraction can therefore be further processed direct withoutother treatment.

The results indicated above and in the Table are also obtained in thesame way in other variants of the method as described below. The onlyexception is Case 2, in which the cocoa butter has a slightly higherwater content because of the liquefaction of the CO in vessel 12.

l. DELIVERY MEANS: LIQUID GAS PUMP:

Case I: As already described above. the following values must be usedhere:

are here also contained in the cocoa butter.

Absolute preferred values: P,. P- t see case l t sce case 3 With regardto the aroma, the remarks made in connection with case 3 are alsoapplicable here.

CONVEYOR: C B COMPRESSOR The apparatus differs from that shown in thedrawing only in that the conveyer is here a compressor. Before enteringthe compressor the current of gas must therefore be brought tosupercritical temperatures in the heat exchanger 21, while in theexchanger 14 only the excess heat of compression is removed. Cases 1 to4 can likewise be carried out, but here the heat exhchanges havedifferent functions. In practice they are connected together, so thatfor example the heat of compression is partly used to supply theevaporation heat to the vessel 12 or to the exchanger. 21. This alsoapplies correspondingly to operation with a liquid gas pump.

Depending on the parameters applicable to the pro-- cess, the processingtimes are between 0.5 and 7 hours.

The removal of the cocoa butter from the vessel 12 is particularlysimple if the temperature in 12 is kept at or slightly above the clearmelting point of the butter, if the pressure of the gas is lowered to afew atmospheres gauge and if the liquid cocoa butter is then run offthrough valve 23, degasification being affected simultaneously. It ismoreover a particular feature of the process that with the exception ofthe pump and the automatic valves there are no moving parts. Theinstallation can be cleaned to remove residues of fat in the pipes, whennecessary, by operating the cycle without filling the tube 13, thuscollecting the residues in the vessel 12, from which they are removed.

EXAMPLES l. 2 kg of crushed cocoa nibs were processed in theinstallation illustrated in the drawing, Case 1, as fol-- lows:

Time: 5 hours Extraction pressure P 320 at. gauge Extraction temperatureI, 45C

disintegration pressure P 56 at. gauge disintegration temperature t 38CResults: 830 g (274% of the fat fraction contained) of slightlyyellowish cocoa butter with a mild aroma were obtained.

Analytical data: see table. 2. 2 kg of cocoa mass were processed in theinstallation shown in the drawing. Case 2, as follows:

Time: 4 hours Extraction pressure P 350 at. gauge Extraction temperature1 60C disintegration pressure P 53 at. gauge disintegration temperatureC.

Result: 1 160 g (Q9971 of the extractable fat fraction) of light yellowcocoa butter with a strong aroma were obtained. The residue left behindwas a powdery material with a slightly lightened colour as compared withthe starting material and likewise with a good aroma.

' Analytical data: see Table.

Table 2. A method according to claim 1 including the further step ofrecovering the cocoa butter from the resulting extract.

3. A method according to claim 2 wherein said recovery step is effectedby lowering the pressure to below the critical pressure whilemaintaining the temperature above the critical temperature.

4. A method according to claim 2 wherein said recovery step is effectedby lowering the pressure below the critical pressure while maintainingthe temperature below the critical temperature.

5. A method according to claim 1 wherein said gas is selected from thegroup consisting of prepurified N 0, SF CHFg, ethane. ethylene, CF Cl,CHF- Cl. CF. ,=CH C F and C0 6. A method according to claim 1 whereinsaid gas is carbon dioxide.

7. A method according to claim 6 wherein the pressure at which theextraction is conducted is from about Fat content Material Degree ofExtraction Saponitication number Example I: Crushed cocoa nibs.unprocessed. "/2 Cocoa butter from above Extracted crushed nibs Example2: Cocoa mass. unprocessed. "/1 Cocoa butter from above Cocoa powder,residue Ordinary commercial cocoa butter l92-l97 Iodine number Clearmelting point Acid number 200 atmospheres to about 400 atmospheresgauge.

8. A method according toclaim 6 wherein the temperature at which theextraction is conducted is from about 40 to about 60C.

9. A method according to claim 7, wherein the temperature at which theextraction is conducted is from about 40 to about 60C.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTIONPATENT NO. 3,923,847 DATED December 2, 1975 |NVENTOR(5) I WilhelmRoselius, Otto Vitzthum and, Peter Hubert It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 1, line 34, change "Gordain" to "Gordian".

Column 4, line 7, change to 5 a Signed and Scaled this A ttes t:

RUTH C. MASON Arresting Officer C. MARSHALL DANN Commissioner oflaremsand Trademarks

1. A METHOD FOR THE PRODUCTION OF COCOA BUTTER FROM COCOA MASS OR FROMROASTED OOR UNROASTED COCOA NIBS COMPRISNG THE STEP OF CONTACTING SAIDCOCOA PRODUCT WITH A FOOD-ACCEPTABLE SOLVENT GAS WHICH IS SUPERCRITICALIN RESPECT OF TEMPERATURE AND PRESSURE FOR EXTRACTION OF SAID COCOABUTTER BY THE SOLVENT GAS, AND REMOVING THE SOLVENT GAS BEARING THECOCOA BUTTER FROM THE RESIDUE OF SAID COCOA PRODUCT.
 2. A methodaccording to claim 1 including the further step of recovering the cocoabutter from the resulting extract.
 3. A method according to claim 2wherein said recovery step is effected by lowering the pressure to belowthe critical pressure while maintaining the temperature above thecritical temperature.
 4. A method according to claim 2 wherein saidrecovery step is effected by lowering the pressure below the criticalpressure while maintaining the temperature below the criticaltemperature.
 5. A method according to claim 1 wherein said gas isselected from the group consisting of prepurified N2O, SF6, CHF3,ethane, ethylene, CF3 Cl, CHF2Cl, CF2 CH2, C3 F8 and CO2.
 6. A methodaccording to claim 1 wherein said gas is carbon dioxide.
 7. A methodaccording to claim 6 wherein the pressure at which the extraction isconducted is from about 200 atmospheres to about 400 atmospheres gauge.8. A method according to claim 6 wherein the temperature at which theextraction is conducted is from about 40* to about 60*C.
 9. A methodaccording to claim 7, wherein the temperature at which the extraction isconducted is from about 40* to about 60*C.